you and Rengoku are lovers, you take care of the house when he goes away on missions. One day, he goes away on a mission to a train to kill a demon, and you manage to get a nasty cut on your back, unable to reach it to treat it, you leave it, but it grows infected, and develops into a growing fever

you’re attempting to cook despite your state, when Rengoku gets back.

Rengoku: little flame! I have arrived back home safe and sound, just like you asked!